package com.hd.hdxgddcommon.utils;

import javax.servlet.http.HttpServletRequest;

/**
 * 获取IP地址
 */
public class IPUtils {
    /**
     * 获取IP地址
     * <p>
     * 使用 nginx 等反向代理软件, 则不能通过request.getRemoteAddr()获取IP地址
     * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，
     * X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
     */
    public static String getRealIp(HttpServletRequest request) {
        String ip ;
        ip = request.getHeader("x-forwarded-for");
        if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (StringUtils.isEmpty(ip) || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }
    public static boolean internalIp(byte[] addr) {
        final byte b0 = addr[0];
        final byte b1 = addr[1];
        //10.x.x.x/8
        final byte SECTION_1 = 0x0A;
        //172.16.x.x/12
        final byte SECTION_2 = (byte) 0xAC;
        final byte SECTION_3 = (byte) 0x10;
        final byte SECTION_4 = (byte) 0x1F;
        //192.168.x.x/16
        final byte SECTION_5 = (byte) 0xC0;
        final byte SECTION_6 = (byte) 0xA8;
        switch (b0) {
            case SECTION_1:
                return true;
            case SECTION_2:
                if (b1 >= SECTION_3 && b1 <= SECTION_4) {
                    return true;
                }
            case SECTION_5:
                switch (b1) {
                    case SECTION_6:
                        return true;
                }
            default:
                return false;
        }
    }

    public static boolean internalIp(String ip) {
        String[] ips = ip.split("\\.");
        byte[] ipbs = new byte[4];
        if (ips.length == 4) {
            for (int i = 0; i < ipbs.length; i++) {
                ipbs[i] = (byte) Integer.parseInt(ips[i]);
            }
            return internalIp(ipbs);
        } else {
            return false;
        }
    }

    private static final String IP_REX = "((1[0-9][0-9]\\.)|(2[0-4][0-9]\\.)|(25[0-5]\\.)|([1-9][0-9]\\.)|([0-9]\\.)){3}((1[0-9][0-9])|(2[0-4][0-9])|(25[0-5])|([1-9][0-9])|([0-9]))";

    public static boolean isIp(String ip) {
        return StringUtils.isBlank(ip) ? false : ip.matches(IP_REX);

    }
}
